WO2014069239A1

WO2014069239A1 - Power feeding device and wireless power feeding system

Info

Publication number: WO2014069239A1
Application number: PCT/JP2013/078130
Authority: WO
Inventors: 義久天野
Original assignee: シャープ株式会社
Priority date: 2012-10-30
Filing date: 2013-10-17
Publication date: 2014-05-08
Also published as: TW201429110A

Abstract

A power feeding device having N power feeding coils from a first system to an Nth system (N is an integer no less than two) to wirelessly feed power to a power receiving device having N power receiving coils from a first system to an Nth system, the power feeding device performing the wireless power feeding by allowing AC current to flow in each of the N power feeding coils and generating electromagnetic induction in each system due to the power feeding coils and the power receiving coils. The N power feeding coils are each arranged substantially on the same plane, and the directions of the AC currents flowing in the adjoining power feeding coils are continuously flowing in the reverse of each other.

Description

Power supply device and wireless power supply system

The present invention relates to a power supply apparatus that performs wireless power supply and a wireless power supply system having the same.

In recent years, so-called wireless power feeding technology that performs non-contact power transmission by electromagnetic coupling between coils is becoming widespread. The technology related to “Okudashi Charging (registered trademark)” promoted in the field of mobile phones, starting with “AQUOS PHONE (registered trademark) SH-13C” released in August 2011, is representative.

FIG. 8 schematically shows a set of a charger 811 and an electric device 812 as an example of a device to which the wireless power feeding system is applied. 8A shows a perspective view of a state where the charger 811 and the electric device 812 are separated from each other, and FIG. 8B shows a side view of the state where the electric device 812 is placed on the charger 811. A cross-sectional view is shown. Note that the charger 811 includes a power feeding device (wireless power feeding device), and the electric device 812 includes a power receiving device (wireless power receiving device).

Note that FIG. 8B more specifically shows a state where the charger 811 is placed on the desk and the electric device 812 is placed on the charger 811. When charging the electric device 812, it is only necessary to place the electric device 812 on the charger 811 as shown in FIG. Even if the cable connection is not performed simply by placing the cable in this way, electric power of a maximum of 5 W is wirelessly transmitted from the power feeding device to the power receiving device, and the electric device 812 can be charged.

Most of the wireless power supply compatible devices currently on the market are designed in accordance with a standard (commonly known as “Qi”, hereinafter referred to as “Qi standard”) defined by an industry group, WPC (Wireless Power Consortium). Details of the Qi standard are disclosed in a standard document (Non-Patent Document 1), and outlines of internal circuit configurations of a power feeding device and a power receiving device are also defined.

An example of the internal circuit configuration of the wireless power supply system is shown in FIG. The part of the power feeding device 611 quotes Figure 3-8 almost as it is, and the part of the power receiving device 612 quotes Figure 4-3 almost as it is.

In the power feeding device 611, the power of the DC power source 601 is converted into AC power by the inverter circuit 614 and supplied to the power feeding coil L611. Accordingly, electromagnetic induction occurs in the power feeding coil L611 and the power receiving coil L612, and AC power is wirelessly transmitted from the power feeding device 611 to the power receiving device 612.

In order to improve performance, resonant capacitors (C611, C612) are inserted before and after these coils. In the power receiving device 612, AC power received by the power receiving coil L 612 is returned to DC power by the rectifier circuit 617 and output from the output terminal 602. The output power is used on the device side provided with the power receiving device 612.

Further, the power supply device 611 is provided with a control circuit 613 for controlling the inverter circuit 614. The control circuit 613 controls On / Off switching of each switch element (S1 to S4) in the inverter circuit 614 so that power conversion is appropriately performed.

In addition, communication of control information in accordance with the Qi standard is necessary between the power feeding device 611 and the power receiving device 612. Therefore, in the power feeding device 611, the signal receiving circuit 615 is connected to the power feeding coil L611 via the capacitor C613. In the power receiving device 612, a load modulation circuit 616 is connected to the power receiving coil L612. Thereby, communication is possible between the power feeding device 611 and the power receiving device 612.

FIG. 7 shows an example of the coil L600 used as the power feeding coil L611 and the power receiving coil L612, and the surrounding structure. A coil L600 shown in FIG. 7 is an Al coil disclosed in section 3.2.1.1.1 of Non-Patent Document 1, and is the most common coil at present. As shown in FIG. 7, the coil L <b> 600 is a circular coil formed by winding a copper wire, and is attached to the surface of the magnetic plate 704. Further, both ends of the coil L600 are connected to wiring patterns (P711, P712) provided on the circuit board 703 by soldering.

JP 2010-187495 A

Even with the above-described conventional wireless power supply system, no particular problem has occurred as long as a low power of about 5 W, which was assumed in the original Qi standard, is output. However, when the trend toward higher output increases with the spread of the Qi standard and a relatively large power output is required, the conventional wireless power supply system has two main problems.

First, in order to make the specifications capable of withstanding high power, it is necessary to make the components of the wireless power supply system expensive parts with high power durability. Therefore, the problem that the manufacturing cost of the wireless power supply system increases remarkably is cited as a first problem.

Moreover, unnecessary magnetic field radiation that leaks to the periphery of the wireless power feeding system increases due to the high power output. For this reason, the second problem is that surrounding devices and human bodies are easily affected by unwanted magnetic field radiation.

If a high-power AC magnetic field is received, there is a risk of causing malfunctions in the case of surrounding electronic devices and deterioration of sensitivity in the case of wireless devices such as radios. In the case of the human body, it is known that a strong magnetic field causes a stimulating action and the like, and there is a concern about adverse health effects. Therefore, the International Commission on Non-Ionizing Radiation Protection (ICNIRP) has established guidelines for magnetic field strengths that do not adversely affect health, and it is essential to comply with them.

This problem of unnecessary magnetic field radiation becomes more serious as the output power of the wireless power feeder is increased. The charging base for mobile phones already on the market is a low-power device of about 5W, but if power supply technology starts to be adopted in general household appliances such as PCs, TVs, refrigerators, vacuum cleaners, washing machines, etc., 10W Increasing the output to ˜100 W is inevitable, and along with this, suppression technology for unwanted magnetic field radiation becomes an important issue.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a power feeding device that can suppress unnecessary magnetic field radiation while facilitating the realization of an inexpensive and high output wireless power feeding system, and a wireless power feeding system having the power feeding device To do.

The power supply apparatus according to the present invention has N power supply coils from the first series to the Nth series (N is an integer of 2 or more), and has N power reception coils from the first series to the Nth series. On the other hand, a power feeding device that performs wireless power feeding, in which an alternating current is passed through each of the N power feeding coils, and electromagnetic induction is generated by the power feeding coil and the power receiving coil in each series. Each of the N power supply coils is disposed on substantially the same plane, and the alternating current directions between the adjacent power supply coils are always opposite to each other.

This configuration makes it possible to suppress unnecessary magnetic field radiation while facilitating the realization of an inexpensive and high-power wireless power feeding system.

A wireless power feeding system according to the present invention includes the power feeding device having the above-described configuration and a power receiving device having N power receiving coils from the first series to the Nth series, and the power receiving apparatus and the power feeding device are positioned. The N power receiving coils are arranged on substantially the same plane so as to face the power supply coils of the same series in the positioned state. The configuration is as follows.

More specifically, the power supply device includes N inverter circuits from the first series to the Nth series, and a control circuit that controls the operation of each of the N inverter circuits. Each of the N inverter circuits is configured to convert DC power into AC power and send the AC power to the power supply coil of the same series. A series of N rectifier circuits and an output terminal, wherein each of the N rectifier circuits converts AC power received from the power receiving coil of the same series into DC power, and the DC power is converted to the output terminal. It is good also as a structure currently formed so that it may send out to.

In addition, a load modulation circuit that transmits a radio signal by load modulation is provided in the power receiving apparatus, and a signal reception circuit that receives the radio signal is provided in the power supply apparatus, and communicates between the load modulation circuit and the signal reception circuit. In the wireless power feeding system configured as described above, the number of the load modulation circuits and the number of the signal reception circuits may be set to one each.

In the wireless power feeding system configured as described above, whether or not a predetermined power feeding start condition is satisfied using the communication at the time of standby when the wireless power feeding is not performed. (K is any one of 1 to N) connected to the power supply coil, the load modulation circuit is connected to the power receiving coil of the Kth series, and the control circuit is connected to the power supply coil in the standby state. While the K-series inverter circuits are driven, the remaining N−1 inverter circuits are stopped, and when the power supply start condition is satisfied, all the N inverter circuits may be driven. .

According to the power feeding device of the present invention, it is possible to suppress unnecessary magnetic field radiation while facilitating the realization of an inexpensive and high-power wireless power feeding system. Moreover, according to the wireless power feeding system according to the present invention, it is possible to enjoy the advantages of the power feeding device according to the present invention.

1 is a configuration diagram of a wireless power feeding system according to a first embodiment. It is explanatory drawing regarding the structure of the feeding coil vicinity which concerns on 1st Embodiment. It is explanatory drawing regarding the principle by which unnecessary electromagnetic field radiation is suppressed. It is a block diagram of the wireless electric power feeding system which concerns on 2nd Embodiment. It is explanatory drawing regarding the structure of the feeding coil vicinity which concerns on 2nd Embodiment. It is a block diagram regarding the wireless power feeding system of a prior art example. It is explanatory drawing regarding the structure of the coil of a prior art example. It is explanatory drawing regarding the apparatus with which the wireless electric power feeding system was applied.

Embodiments of the present invention will be described below by taking the first embodiment and the second embodiment as examples.

1. First Embodiment [Overall Configuration of Wireless Power Supply System]
First, the first embodiment will be described. FIG. 1 is a configuration diagram of a wireless power feeding system 1 according to the first embodiment. As shown in FIG. 1, the wireless power feeding system 1 includes a power feeding device 111 (wireless power feeding device) and a power receiving device 112 (wireless power receiving device). The wireless power supply system 1 is configured to conform to the Qi standard.

The power supply device 111 includes a DC power supply unit 101, the control circuit 113, the inverter circuits (114 _a, 114 _b), the signal receiving circuit 115, the capacitors _{_{(C1 a, C1 b, C3}} ), and the feeding coil (L1 _a, L1 _b ). The power receiving device 112, an output terminal 102, the load modulation circuit 116, and a respective rectifier circuits (127 _a, 127 _b), each receiving coil (L2 _a, L2 _b), and each capacitor (C2 _a, C2 _b) .

Further, the wireless power feeding system 1 has first and second power transmission mechanisms as shown in FIG. 1 as a mechanism for performing wireless power transmission from the power feeding device 111 to the power receiving device 112. In the following description, the first series of power transmission mechanisms may be simply referred to as “first series”, and the second series of power transmission mechanisms may be simply referred to as “second series”.

The first series, the control circuit 113, the inverter circuit 114 _a, a signal receiving circuit 115, a load modulation circuit 116, the capacitors _{_{(C1 a, C2 a, C3}} ), the feeding coil L1 _a, the power receiving coil L2 _a, and a rectifier circuit 127 _a is included. The second series includes an inverter circuit 114 _b , capacitors (C 1 _b , C 2 _b ), a feeding coil L 1 _b , a receiving coil L 2 _b , and a rectifier circuit 127 _b .

In addition, elements having a subscript “a” or “b” in the quotation marks are basically provided in both the first series and the second series, and the subscript “a” is the first. This means that the subscript is of the series, and the subscript “b” is that of the second series. As is clear from FIG. 1, the wireless power feeding system 1 has a configuration in which a first power transmission mechanism and a second power transmission mechanism are provided in parallel between the DC power supply unit 101 and the output terminal 102. .

Although the power feeding device 111 and the power receiving device 112 are structurally separated from each other, the wireless power feeding system 1 is configured so that the power feeding device 111 and the power receiving device 112 are appropriately positioned (so that the power feeding coil and the power receiving coil of each series face each other). The wireless power supply is possible (configuration shown in FIG. 1). When the wireless power feeding system 1 performs wireless power feeding, positioning is performed in this manner in advance, and wireless power feeding proceeds while maintaining the positioned state.

The DC power supply unit 101 is configured by, for example, a battery or an AC adapter connected to a commercial power supply, and functions as a DC power supply. The DC power supply unit 101 supplies DC power to each inverter circuit (114 _a , 114 _b ).

The inverter circuit 114 _a is a full-bridge inverter circuit having a plurality of switch elements (S1 _a to S4 _a ), and the inverter circuit 114 _b is a full circuit having a plurality of switch elements (S1 _b to S4 _b ). This is an inverter circuit having a bridge structure.

In the inverter circuit 114 _a, one end of the switch elements S1 _a and S3 _a is connected to the DC power supply unit 101, one end of the switching element S2 _a and S4 _a is grounded. The other end of the switch element S1 _a, together with the leads directly to the other end of the switch element S2 _a, is connected to one end of the feeding coil L1 _a via capacitor C1 _a. The other end of the switch element S3 _a is connected to the other ends and feeding coil L1 _a switching element S4 _a.

In the inverter circuit 114 _b , one end of the switch elements S1 _b and S3 _b is connected to the DC power supply unit 101, and one end of the switch elements S2 _b and S4 _b is grounded. The other end of the switch element S1 _b, together with the leads directly to the other end of the switch element S2 _b, is connected to one end of the feeding coil L1 _b via the capacitor C1 _b. The other end of the switch element S3 _b is connected to the other ends and feeding coil L1 _b of the switching element S4 _b.

Each inverter circuit (114 _a , 114 _b ) has the above-described configuration, and converts DC power supplied from the DC power supply unit 101 into AC power by switching each switch element on and off. The inverter circuit 114 _a sends a AC power generated by the conversion to the feeding coil L1 _a, inverter circuit 114 _b sends the AC power generated by the conversion to the feeding coil L1 _b.

On / off switching of each switch element in each inverter circuit (114 _a , 114 _b ) is controlled by the control circuit 113. That control circuit 113, as the inverter circuits (114 _a, 114 _b) to work properly, generating and outputting the control signals (G1 ~ G4) for performing an on / off switch to the switching elements To do. For example, when each switch element is an FET, the control circuit 113 generates a pulse signal in which H level and L level appear alternately as each control signal (G1 to G4), and outputs it to the gate of each FET.

The control circuit 113 is connected to the switch elements S1 _a and S1 _b via the same wiring, and outputs a control signal G1 to these switch elements via the wiring. The control circuit 113 is connected via the same wiring to the switch element S2 _a and S2 _b, and outputs a control signal G2 via the wiring for these switch elements. The control circuit 113 is connected via the same wiring to the switching element S3 _a and S3 _b, and outputs a control signal G3 through the wiring for these switch elements. The control circuit 113 is connected via the same wiring to the switch element S4 _a and S4 _b, and outputs a control signal G4 via the wiring for the switch elements.

As described above, the pair of switch elements S1 _a and S1 _b , the pair of switch elements S2 _a and S2 _b , the pair of switch elements S3 _a and S3 _b , and the pair of switch elements S4 _a and S4 _b operate in synchronization with each other. Will do. Therefore the inverter circuits (114 _a, 114 _b) will output the AC power of the same phase in synchronization with each other.

The signal receiving circuit 115 is connected to the feeding coil L1 _a via the capacitor C3, and receives the radio signal Sr from the power receiving device 112 side (load modulation circuit 116). Note that as the driving power of the signal receiving circuit 115, a part of the transmission power in the first series is used, but other forms may be used.

One end of the power receiving coil L2 _a via capacitor C2 _a, is connected to one input terminal of the rectifier circuit 127 _a. The other end of the power receiving coil L2 _a is connected to the other input ends of the rectifier circuit 127 _a. One end of the power receiving coil L2 _b via the capacitor C2 _b, is connected to one input terminal of the rectifier circuit 127 _b. The other end of the power receiving coil L2 _b is connected to the other input ends of the rectifier circuit 127 _b. Each capacitor (C1 _a , C1 _b , C2 _a , C2 _b ) is a resonant capacitor inserted before and after the power feeding / receiving coil in order to improve performance.

The load modulation circuit 116 is connected to the power receiving coil L2 _a through capacitor C2 _a, it transmits a radio signal Sr due to load modulation. Note that as the driving power of the load modulation circuit 116, a part of the transmission power in the first series is used, but other forms may be used.

As described above, the radio signal Sr is received by the signal receiving circuit 115 on the power feeding apparatus 111 side. Accordingly, communication related to wireless power feeding between the power feeding device 111 and the power receiving device 112 is possible. Since the configuration of the signal receiving circuit 115 and the load modulation circuit 116 and the specific form of the communication are well known, detailed description is omitted here.

The rectifier circuit 127 _a converts AC power sent from the power receiving coil L < _b > 2 _a into DC power, and sends the DC power to the output terminal 102. The rectifier circuit 127 _b converts the AC power sent from the power receiving coil L < _b > 2 _b into DC power, and sends the DC power to the output terminal 102.

The output terminal 102 is connected to the secondary battery in an electrical equipment having a power receiving device 112 (not shown), and outputs the synthesized power received from each rectifier circuit (127 _a, 127 _b). Thereby, the DC power sent from each rectifier circuit (127 _a , 127 _b ) is supplied to the secondary battery via the single output terminal 102, and is used as drive power for the electric device or the like. In the present embodiment, the output power from the output terminal 102 is supplied to the secondary battery, but the supply destination of the output power is not limited to such a form.

FIG. 2 illustrates a structure (mounting form) in the vicinity of each power supply coil (L1 _a , L1 _b ) in the power supply apparatus 111. Each of the feeding coils (L1 _a , L1 _b ) is a circular coil formed by winding a copper wire in the same direction, and is attached to the surface of the magnetic plate 304 so as to be substantially adjacent on the same plane. Closely arranged. Further, both ends of each of the power feeding coils (L1 _a , L1 _b ) are soldered and connected to wiring patterns (P311, P312, P321, P322) provided on the circuit board 303.

Wiring patterns P311 leads between the switch element S3 _a and S4 _a, the wiring pattern P312 is connected to one end of the capacitor C1 _a. Wiring patterns P321 leads to one end of the capacitor C1 _b, the wiring pattern P322 is connected between the switching element S3 _b and S4 _b.

The three wiring patterns (P311, P312 and P321) are arranged on the front surface side of the circuit board 303, while the remaining wiring patterns P322 are arranged on the back surface side of the circuit board 303 so as to cross three-dimensionally with the wiring pattern P321. Has been placed. The reason for adopting such a three-dimensional intersection is that the alternating currents flowing in the respective feeding coils (L1 _a , L1 _b ) are in opposite directions (the significance of the reverse directions will be clarified in the following description). ).

Each power receiving coil (L2 _a , L2 _b ) is arranged on substantially the same plane so as to face the same series of power feeding coils in a state where the power receiving device 112 and the power feeding device 111 are positioned as described above.

The power receiving device 112 and the power supply device 111 is positioned, when the power feeding is performed in the wireless power supply system 1, the control circuit 113, the inverter circuits (114 _a, 114 _b) are the control signals so as to drive (G1 ~ G4) Is output.

Thereby, in each of the first series and the second series, the power receiving coil generates an electromotive force by an alternating magnetic field generated by the feeding coil (that is, by electromagnetic induction), and generates alternating current power. That is, electric power is transmitted from the feeding coil to the receiving coil by mutual induction magnetic field coupling. In this manner, wireless power feeding from the power feeding device 111 to the power receiving device 112 is realized.

[Features of this embodiment]
The wireless power feeding system 1 of the present embodiment has a feature that it is inexpensive and easy to obtain a high output (hereinafter referred to as “first feature”) and a feature that unnecessary magnetic field radiation can be suppressed (hereinafter referred to as “first”). 2 features ”). Hereinafter, these features will be specifically described.

First, the first feature will be explained. As already described, the wireless power feeding system 1 has a plurality of power transmission mechanisms of the first series and the second series in parallel, and the power receiving apparatus 112 combines the power transmitted by these power transmission mechanisms to output terminals. 102 to output. Therefore, even if the power transmission amount in each power transmission mechanism is small, it is possible to easily obtain a high output by combining the transmitted power. For example, when an equivalent power transmission mechanism is applied to each series, it is basically possible to obtain N times the output by providing N series.

In addition, according to the wireless power feeding system 1, compared with a case where only one power transmission mechanism is provided, a power transmission amount required for each power transmission mechanism is small. Therefore, it is possible to use inexpensive parts with low power durability performance as parts constituting each of the power transmission mechanisms, and the manufacturing cost of the wireless power feeding system 1 can be suppressed.

In the wireless power feeding system 1, the control circuit 113, the signal reception circuit 115, and the load modulation circuit 116 are provided only in the first series for cost reduction and synchronization control, and are not provided in the second series. . Therefore, the number of parts can be reduced and the configuration can be simplified as compared with the case where these circuits (113, 115, 116) are also provided in the second series.

That is, this embodiment is not a form in which a plurality of wireless power supply systems illustrated in FIG. 6 are simply bundled, and the manufacturing cost can be further reduced by omitting overlapping circuit components. For the reasons described above, the wireless power feeding system 1 has the first feature.

Next, the second feature will be described. When attention is paid to the direction of the alternating current flowing through the power supply coil, the directions of the alternating current in the power supply coil L1 _a and the power supply coil L1 _b (adjacent power supply coils) are always opposite to each other.

That is, for example, with reference to the current flowing in the counterclockwise direction (the same applies to the clockwise direction), the waveform of the alternating current flowing in the feeding coil L1 _a and the waveform of the alternating current flowing in the feeding coil L1 _b are synchronized and opposite in phase. It becomes the relationship. It should be noted that in the portions (proximity portion CS shown in FIG. 2) where the respective feeding coils (L1 _a , L1 _b ) are close to each other, the directions of the alternating currents of the respective feeding coils (L1 _a , L1 _b ) are always substantially the same direction. It becomes.

As described above, in this embodiment, the directions of the alternating currents between the adjacent feeding coils are always opposite to each other. Therefore, the feeding coil is based on the same principle as the invention of the prior application (Japanese Patent Application No. 2012-121741) by the present applicant. And unnecessary magnetic field radiation (unnecessary electromagnetic field radiation) leaking from the receiving coil (power supply / receiving coil) to the surroundings is suppressed.

In other words, when power is supplied from the power supply device 111 to the power reception device 112, a part of the magnetic field lines (for example, about a fraction) of the first system power supply / power reception coils (L1 _a , L2 _a ) , is sucked into the feed-receiving coil of the second system bent the path (L1 _{_b,} L2 _b), a part of the magnetic field lines exiting from the feeding-receiving coil of the second system (L1 _{_b,} L2 _b) (e.g., The course is bent and the path is bent and sucked into the power feeding / receiving coils (L1 _a , L2 _a ) of the first system. As a result, the first power feeding / receiving coil (L1 _a , L2 _a ) and the second power feeding / receiving coil (L1 _b , L2 _b ) absorb each other's magnetic field lines so that the magnetic field lines are compactly folded. It is suppressed from spreading far away.

Further, the principle of suppressing unnecessary electromagnetic field radiation from another viewpoint will be described with reference to FIG. FIG. 3 schematically shows the positional relationship among the power receiving coils (L2 _a , L2 _b ), the current Ia flowing through the power feeding coil L1 _a , and the current Ib flowing through the power feeding coil L1 _b .

It is known that the strength of the low frequency magnetic field attenuates in inverse proportion to the square of the distance. For example, at the point A in the vicinity of the power receiving coil, the distance from the current Ia and the distance from the current Ib are significantly unbalanced. Therefore, at point A, the magnetic field strength is determined only by the current Ia that is substantially closer, so that strong magnetic field coupling occurs.

However, at a distant point B, for example, the distance from the current Ia is almost equal to the distance from the current Ib. Therefore, at point B, the two magnetic fields having substantially the same intensity and opposite phases cancel each other, so that the magnetic field intensity can be kept low. As described above, in the present embodiment, contradictory demands of strong magnetic field coupling near the power receiving coil and abrupt attenuation in the distance are simultaneously satisfied.

For the reasons described above, the wireless power feeding system 1 has the second feature. By suppressing unnecessary magnetic field radiation that leaks to the surroundings, it is possible to reduce electromagnetic interference to surrounding electronic devices and magnetic field exposure to surrounding human bodies. The direction of the alternating current between adjacent feeding coils in the present invention is preferably completely “always opposite to each other”, but an error within a range not departing from the main point of obtaining the second feature (for example, There may be things that do not reverse each other for a very short time.

In addition, when a plurality of power transmission mechanisms are simply arranged in parallel, there is generally a problem that parasitic coupling occurs between a plurality of power feeding coils and the operation is hindered. The second feature described above can also be regarded as an effect of suppressing unwanted magnetic field radiation by taking advantage of this parasitic coupling.

2. Second Embodiment [Overall Configuration of Wireless Power Supply System]
Next, a second embodiment will be described. FIG. 4 is a configuration diagram of the wireless power feeding system 1 according to the second embodiment. As illustrated in FIG. 4, the wireless power feeding system 1 includes a power feeding device 111 (wireless power feeding device) and a power receiving device 112 (wireless power receiving device). The wireless power supply system 1 is configured to conform to the Qi standard.

The power supply device 111 includes a DC power supply unit 101, the control circuit 113, the inverter circuits (114 _a ~ 114 _c), the signal receiving circuit 115, a switch circuit 123, the capacitors _{_{(C1 a ~ C1 c, C3}} ), and the feeding coil (L1 _a to L1 _c ). The power receiving device 112 includes an output terminal 102, a load modulation circuit 116, each rectifier circuit (127 _a to 127 _c ), each power receiving coil (L2 _a to L2 _c ), and each capacitor (C2 _a to C2 _c ). .

Further, the wireless power feeding system 1 has first to third power transmission mechanisms as shown in FIG. 4 as a mechanism for performing wireless power transmission from the power feeding device 111 to the power receiving device 112. In the following description, the first series power transmission mechanism is simply referred to as “first series”, the second series power transmission mechanism is simply referred to as “second series”, and the third series power transmission mechanism is simply referred to as “third series”. May be called.

The first series, the control circuit 113, the inverter circuit 114 _a, a signal receiving circuit 115, a load modulation circuit 116, the capacitors _{_{(C1 a, C2 a, C3}} ), the feeding coil L1 _a, the power receiving coil L2 _a, and a rectifier circuit 127 _a is included. The second series includes an inverter circuit 114 _b , capacitors (C 1 _b , C 2 _b ), a feeding coil L 1 _b , a receiving coil L 2 _b , and a rectifier circuit 127 _b . The third series includes an inverter circuit 114 _c , capacitors (C1 _c , C2 _c ), a feeding coil L1 _c , a receiving coil L2 _c , and a rectifier circuit 127 _c .

In addition, for elements having subscripts “a” to “c” in the quotation marks, the equivalents are provided in any of the first to third series, and the subscript “a” is the first series. The subscript “b” represents the second series, and the “c” subscript represents the third series. As is clear from FIG. 4, the wireless power feeding system 1 has a configuration in which the first to third power transmission mechanisms are provided in parallel between the DC power supply unit 101 and the output terminal 102.

Although the power feeding device 111 and the power receiving device 112 are structurally separated from each other, the wireless power feeding system 1 is configured so that the power feeding device 111 and the power receiving device 112 are appropriately positioned (so that the power feeding coil and the power receiving coil of each series face each other). The wireless power feeding is possible (configuration shown in FIG. 4). When the wireless power feeding system 1 performs wireless power feeding, positioning is performed in this manner in advance, and wireless power feeding proceeds while maintaining the positioned state.

The DC power supply unit 101 is configured by, for example, a battery or an AC adapter connected to a commercial power supply, and functions as a DC power supply. The DC power supply unit 101 supplies DC power to each inverter circuit (114 _a to 114 _c ).

The inverter circuit 114 _a is an inverter circuit of the full bridge structure having a plurality of switching elements (S1 _{_a} ~ S4 _a). The inverter circuit 114 _b is a full-bridge inverter circuit having a plurality of switch elements (S1 _b to S4 _b ). The inverter circuit 114 _c is a full-bridge inverter circuit having a plurality of switch elements (S1 _c to S4 _c ).

In the inverter circuit 114 _c , one end of the switch elements S1 _c and S3 _c is connected to the DC power supply unit 101, and one end of the switch elements S2 _c and S4 _c is grounded. The other end of the switch element S1 _c, together with the leads directly to the other end of the switch element S2 _c, is connected to one end of the feeding coil L1 _c via the capacitor C1 _c. The other end of the switch element S3 _c is connected to the other ends and feeding coil L1 _c of the switching element S4 _c.

Each inverter circuit (114 _a to 114 _c ) has the above-described configuration, and converts DC power supplied from the DC power supply unit 101 into AC power by switching each switch element on and off. The inverter circuit 114 _a sends the AC power generated by the conversion to the feeding coil L1 _a , and the inverter circuit 114 _b sends the AC power generated by the conversion to the feeding coil L1 _b , and the inverter circuit 114 _c Sends the AC power generated by the conversion to the feeding coil L1 _c .

On / off switching of each switch element in each inverter circuit (114 _a to 114 _c ) is controlled by the control circuit 113. That control circuit 113, so that each inverter circuit (114 _a ~ 114 _c) to work properly, generating and outputting the control signals (G1 ~ G4) for performing an on / off switch to the switching elements To do. For example, when each switch element is an FET, the control circuit 113 generates a pulse signal in which H level and L level appear alternately as each control signal (G1 to G4), and outputs it to the gate of each FET.

The control circuit 113 is connected to the switch elements S1 _a , S2 _b , and S1 _c via the same wiring, and outputs a control signal G1 to these switch elements via the wiring. The control circuit 113 is connected to the switch elements S2 _a , S1 _b , and S2 _c via the same wiring, and outputs a control signal G2 to these switch elements via the wiring. The control circuit 113 is connected to the switch elements S3 _a , S4 _b , and S3 _c via the same wiring, and outputs a control signal G3 to these switch elements via the wiring. The control circuit 113 is connected to the switch elements S4 _a , S3 _b , and S4 _c via the same wiring, and outputs a control signal G4 to these switch elements via the wiring.

Thus, a set of each switch element (S1 _a , S2 _b , S1 _c ), a set of each switch element (S2 _a , S1 _b , S2 _c ), a set of each switch element (S3 _a , S4 _b , S3 _c ) , And the switch elements (S4 _a , S3 _b , S4 _c ) operate in synchronization with each other. Therefore, the inverter circuits (114 _a to 114 _c ) output AC power in synchronization with each other.

The inverter circuit 114 _a and the inverter circuit 114 _c will output the AC power in-phase to each other. However inverter circuit 114 _b will output the AC power of the reverse phase to the other inverter circuit (114 _a, 114 _c). The reason for this is that the direction of the alternating current flowing through the feeding coil L1 _b is opposite to the alternating current flowing through the other feeding coils (L1 _a , L1 _c ).

The switch circuit 123 has a function of switching conduction / cutoff of the wiring in the middle of the wiring for transmitting the control signals (G1 to G4). In state (disconnected state) in which the switch circuit 123 is cut off the wire, the control signals (G1 ~ G4) is the inverter circuit 114 _a of the first sequence is transmitted, a second series and a third series the inverter circuit (114 _b, 114 _c) are not transmitted.

One end of the power receiving coil L2 _a via capacitor C2 _a, is connected to one input terminal of the rectifier circuit 127 _a. The other end of the power receiving coil L2 _a is connected to the other input ends of the rectifier circuit 127 _a. One end of the power receiving coil L2 _b via the capacitor C2 _b, is connected to one input terminal of the rectifier circuit 127 _b. The other end of the power receiving coil L2 _b is connected to the other input ends of the rectifier circuit 127 _b. One end of the power receiving coil L2 _c via the capacitor C2 _c, is connected to one input terminal of the rectifier circuit 127 _c. The other end of the power receiving coil L2 _c is connected to the other input end of the rectifier circuit 127 _c . Each of the capacitors (C1 _a to C1 _c , C2 _a to C2 _c ) is a resonant capacitor inserted before and after the power feeding / receiving coil in order to improve performance.

The load modulation circuit 116 is connected to the power receiving coil L2 _a through capacitor C2 _a, it transmits a radio signal Sr due to load modulation. Note that as the driving power of the load modulation circuit 116, a part of the transmission power in the first series is used, but other forms may be used. As described above, the radio signal Sr is received by the signal receiving circuit 115 on the power feeding apparatus 111 side. Accordingly, communication related to wireless power feeding between the power feeding device 111 and the power receiving device 112 is possible.

The rectifier circuit 127 _a converts AC power sent from the power receiving coil L < _b > 2 _a into DC power, and sends the DC power to the output terminal 102. The rectifier circuit 127 _b converts the AC power sent from the power receiving coil L < _b > 2 _b into DC power, and sends the DC power to the output terminal 102. The rectifier circuit 127 _c converts the AC power sent from the power receiving coil L2 _c into DC power, and sends the DC power to the output terminal 102.

The output terminal 102 is connected to the secondary battery in an electrical equipment having a power receiving device 112 (not shown), and outputs the synthesized power received from each rectifier circuit (127 _a ~ 127 _c). As a result, the DC power sent from each of the rectifier circuits (127 _a to 127 _c ) is supplied to the secondary battery via the single output terminal 102, and is used as drive power for the electric device. In the present embodiment, the output power from the output terminal 102 is supplied to the secondary battery, but the supply destination of the output power is not limited to such a form.

FIG. 5 illustrates a structure (mounting form) in the vicinity of each of the power supply coils (L1 _a to L1 _c ) in the power supply apparatus 111. Each of the feeding coils (L1 _a to L1 _c ) is a circular coil formed by winding a copper wire in the same direction, and is disposed on substantially the same plane by being attached to the surface of the magnetic plate 504. The feeding coils (L1 _a to L1 _c ) are arranged in the order of L1 _a , L1 _b , L1 _c , the feeding coils L1 _a and L1 _b are close to each other and are close to each other, and the feeding coil L1 _b L1 _c are arranged to approach substantially as adjacent. Further, both ends of each of the power feeding coils (L1 _a to L1 _c ) are soldered and connected to wiring patterns (P511, P512, P521, P522, P531, and P532) provided on the circuit board 503.

Wiring patterns P511 leads between the switch element S3 _a and S4 _a, the wiring pattern P512 is connected to one end of the capacitor C1 _a. Wiring patterns P521 leads between the switch element S3 _b and S4 _b, the wiring pattern P522 is connected to one end of the capacitor C1 _b. Wiring patterns P531 leads between the switch element S3 _c and S4 _c, the wiring patterns P532 is connected to one end of the capacitor C1 _c.

Further, each wiring pattern (P511, P512, P521, P522, P531, P532) is arranged on the surface side of the circuit board 503. Unlike the case of the first embodiment, the three-dimensional intersection between the wiring patterns is not adopted.

Each of the power receiving coils (L2 _a to L2 _c ) is arranged on substantially the same plane so as to face the same series of power feeding coils in a state where the power receiving device 112 and the power feeding device 111 are positioned as described above.

When the power feeding is performed in the wireless power supply system 1, the control circuit 113, the inverter circuits (114 _a ~ 114 _c) outputs the control signals (G1 ~ G4) to drive. As a result, in each of the first to third series, the power receiving coil generates an electromotive force by an AC magnetic field generated by the feeding coil (that is, by electromagnetic induction), and generates AC power. That is, electric power is transmitted from the feeding coil to the receiving coil by mutual induction magnetic field coupling. In this manner, wireless power feeding from the power feeding device 111 to the power receiving device 112 is realized.

In a standby state where the wireless power supply from the power supply apparatus 111 to the power reception apparatus 112 is not performed, the signal reception circuit 115 monitors whether or not a predetermined power supply start condition is satisfied using communication with the load modulation circuit 116. To do. The power supply start condition is a condition set in advance so as to be satisfied when preparation for power supply start is completed. For example, the power supply start condition is satisfied when a power receiving device (Qi standard) to be supplied is appropriately positioned and the power supply condition is determined based on the communication result.

Note for the power supply device 111 that enables the above-mentioned monitor (communication with the load modulation circuit 116), even during standby, the inverter circuit 114 _a (inverter circuit of a first series signal receiving circuit 115 is connected) It needs to be driven to some extent. Therefore, in the standby, the control circuit 113 sends the control signals (G1 ~ G4) for thus driving the inverter circuit 114 _a.

However, in the standby state, by the switching circuit 123 is the cut-off state, the control signals (G1 ~ G4) is not sent to the inverter circuit of the second series and the third series (114 _b, 114 _c), these The inverter circuits (114 _b and 114 _c ) are stopped. That is, during standby, the power feeding device 111 drives the first series of inverter circuits 114 _a while stopping the remaining two inverter circuits (114 _b and 114 _c ). As a result, the power feeding device 111 can eliminate unnecessary driving of the inverter circuit and suppress standby power as much as possible.

When the power supply start condition is satisfied, the power supply apparatus 111 shifts from the standby state to the normal operation state. In other words, the power feeding device 111 releases the cutoff state of the switch circuit 123 and drives all the inverter circuits (114 _a to 114 _c ) so that appropriate wireless power feeding to the power receiving device 112 is performed.

The wireless power feeding system 1 of the second embodiment also has the first feature that it is easy to obtain a high output at a low cost, and the second feature that unnecessary magnetic field radiation is suppressed, as in the case of the first embodiment. It has the features of

Note with respect to the second feature, in the case of the second embodiment, together with the power supply coil L1 _a feeding coil L1 _b are adjacent to each other, the feeding coil L1 _b and the power supply coil L1 _c are adjacent to each other. Therefore, in the second embodiment, the directions of the alternating currents in the feeding coil L1 _a and the feeding coil L1 _b are always opposite to each other, and the directions of the alternating currents in the feeding coil L1 _b and the feeding coil L1 _c are always mutually different. It is considered to be the reverse direction.

That is, for example, based on the current flowing in the counterclockwise direction (the same applies to the clockwise direction), the waveform of the alternating current flowing in the feeding coil L1 _a and the waveform of the alternating current flowing in the feeding coil L1 _b are synchronized and opposite in phase. Furthermore, the waveform of the alternating current flowing through the feeding coil L1 _b and the waveform of the alternating current flowing through the feeding coil L1 _c are in a relationship of synchronization and antiphase with each other.

Note that in the portions where the feeding coils (L1 _a , L1 _b ) are close to each other (proximity portion CS1 shown in FIG. 5), the directions of the alternating currents of the feeding coils (L1 _a , L1 _b ) are always substantially the same direction. It becomes. Moreover, in the part (proximity part CS2 shown in FIG. 5) in which each feeding coil (L1 _b , L1 _c ) is close, the direction of the alternating current of each feeding coil (L1 _b , L1 _c ) is always substantially the same direction. It becomes.

As described above, in the second embodiment, there are a plurality of pairs of adjacent feeding coils (here, two pairs of L1 _a and L1 _b and L1 _b and L1 _c ). For the pair, the directions of the alternating currents are always opposite to each other. Therefore, unnecessary magnetic field radiation can be suppressed as much as possible.

3. Others As described above, the power feeding device 111 of each embodiment has N power supply coils from the first series to the Nth series, and has N power receiving coils from the first series to the Nth series. Wireless power feeding is performed on the 112. More specifically, the power feeding device 111 performs the wireless power feeding by causing an alternating current to flow through each of the N power feeding coils and causing electromagnetic induction by the power feeding coil and the power receiving coil in each series. Note that N = 2 in the example of the first embodiment and N = 3 in the example of the second embodiment, but it is also possible to adopt a configuration according to each embodiment and make N 4 or more. .

Further, in the power supply device 111, each of the N power supply coils is arranged on substantially the same plane, and the directions of the alternating currents between adjacent power supply coils are always opposite to each other. Therefore, according to the power feeding device 111, it is possible to suppress unnecessary magnetic field radiation while facilitating the realization of an inexpensive and high-power wireless power feeding system.

In addition, the wireless power feeding system 1 of each embodiment includes a power feeding device 111 and a power receiving device 112 having N power receiving coils from the first series to the Nth series, and the power receiving device 112 and the power feeding device 111 are positioned. The wireless power supply is performed in a state where Each of the N power receiving coils is disposed on substantially the same plane so as to face the power supply coils of the same series in the positioned state.

More specifically, the power feeding apparatus 111 includes N inverter circuits from the first series to the Nth series, and a control circuit 113 that controls the operation of each of the N inverter circuits. Each of the inverter circuits is configured to convert DC power into AC power and send the AC power to the power supply coils of the same series.

The power receiving device 112 further includes N rectifier circuits from the first series to the Nth series and an output terminal 102, and each of the N rectifier circuits receives AC power received from the power receiving coil of the same series. It is configured to convert to DC power and send the DC power to the output terminal.

In the wireless power supply system 1 of each embodiment, a load modulation circuit 116 that transmits a radio signal by load modulation is provided in the power receiving apparatus 112, and a signal reception circuit 115 that receives the radio signal is provided in the power supply apparatus 111. Communication is performed between the modulation circuit 116 and the signal reception circuit 115. Accordingly, information transmission regarding wireless power feeding can be performed between the power feeding apparatus 111 and the power receiving apparatus 112. Further, the number of the load modulation circuits 116 and the number of the signal reception circuits 115 are one, thereby simplifying the configuration.

In addition, the wireless power feeding system 1 according to the second embodiment monitors whether or not a predetermined power feeding start condition is satisfied by using the communication during standby when the wireless power feeding is not performed. The signal receiving circuit 115 is connected to the power supply coil of the Kth series, and the load modulation circuit 116 is connected to the power reception coil of the Kth series. In the example of the second embodiment, K = 1, but K can be any number from 1 to N.

Then, the control circuit 113 of the second embodiment drives the K-th series of inverter circuits at the time of standby, and stops the remaining N−1 inverter circuits, so that the power supply start condition is satisfied. In this case, all the N inverter circuits are driven. Thereby, standby power can be suppressed as much as possible.

The wireless power supply system 1 is suitable for portable electric devices, for example. In this case, the electrical device includes a power receiving device 112 and a secondary battery (connected to the output terminal 102), and is configured to be driven using electric power charged in the secondary battery. The power feeding device 111 is provided in a charger corresponding to the electric device. According to this aspect, it is possible to charge the secondary battery in the electric device by bringing the electric device close to the charger (for example, placing the electric device on the charger). However, the application target of the wireless power feeding system 1 is not limited to such a form.

In addition to the above-described embodiment, the configuration of the present invention can be variously modified without departing from the spirit of the invention. That is, the above-described embodiment is an example in all respects, and should be considered not restrictive. The technical scope of the present invention is shown not by the above description of the embodiment but by the scope of the claims, and it should be understood that all modifications within the meaning and scope equivalent to the scope of the claims are included. It is.

The present invention can be used for an electromagnetic induction type wireless power supply system or the like.

1 wireless power supply system 101 DC power supply 102 output 111 feeding apparatus 112 receiving apparatus 113 the control circuit 114 _a ~ 114 _c inverter circuit 115 signal receiving circuit 116 load modulator 123 switching circuits 127 _a ~ 127 _c

rectifying circuit

303, 503

circuit board

304, 504 Magnetic plate L1 _a to L1 _c Feeding coil L2 _a to L2 _c Power receiving coil C1 _a to C1 _c , C2 _a to C2 _c , C3 Capacitors S1 _a to S4 _a , S1 _b to S4 _b , S1 _c to S4 _c switch element P311, P312, P321, P322 wiring pattern P511, P512, P521, P522, P531, P532 wiring pattern

Claims

N feed coils of the first to Nth series (N is an integer of 2 or more),
A power feeding device that performs wireless power feeding to a power receiving device having N power receiving coils of the first to Nth series,
The wireless power feeding is performed by causing an alternating current to flow through each of the N feeding coils and causing electromagnetic induction by the feeding coil and the receiving coil in each series.
Each of the N feeding coils is disposed on substantially the same plane,
The power feeding device characterized in that the directions of the alternating currents in the adjacent power feeding coils are always opposite to each other.
A power feeding device according to claim 1;
A power receiving device having N power receiving coils of the first to Nth series,
A wireless power feeding system that performs the wireless power feeding with the power receiving device and the power feeding device positioned,
Each of the N power receiving coils is
A wireless power feeding system, wherein the wireless power feeding system is arranged on substantially the same plane so as to face the power feeding coils of the same series in the positioned state.
The power supply device
N inverter circuits from the first series to the N-th series;
A control circuit for controlling the operation of each of the N inverter circuits,
Each of the N inverter circuits is configured to convert DC power into AC power and send the AC power to the power supply coil of the same series,
The power receiving device is:
N rectifier circuits from the first series to the N-th series;
An output terminal,
Each of the N rectifier circuits is configured to convert AC power received from the power receiving coil of the same series into DC power and send the DC power to the output terminal. 2. The wireless power supply system according to 2.
A load modulation circuit for transmitting a radio signal by load modulation is provided in the power receiving device, and a signal receiving circuit for receiving the radio signal is provided in the power feeding device, respectively.
The wireless power feeding system according to claim 3, wherein communication is performed between the load modulation circuit and the signal receiving circuit.
A wireless power feeding system, wherein the number of the load modulation circuits and the number of the signal reception circuits are one each.
The wireless power feeding system according to claim 4, wherein during standby when the wireless power feeding is not performed, the communication is used to monitor whether a predetermined power feeding start condition is satisfied,
The signal receiving circuit is connected to the feeding coil of the Kth series (K is any one of 1 to N),
The load modulation circuit is connected to the power receiving coil of the Kth series,
The control circuit includes:
In the standby time, the inverter circuit of the K-th series is driven, while the remaining N−1 inverter circuits are stopped,
When the power supply start condition is satisfied,
A wireless power feeding system that drives all of the N inverter circuits.